Autophone system.



A. E. STEVENS.

AUTOPHONE SYSTEM.

APPLICATION FILED NOV. 6, 190a.

Patented May 1'7, 1910.

6 SHEETS-SHEET l.

1 N Io INVENTOR M .m-4.

WITNESSES 4a. ATTORNEY A. E. STEVENS. AUTOPHONE SYSTEM,

APPLIOATION FILED NOV. 6', 190a.

Patented May 17,1910.

6 SHEETS-SHEET 2.

INVENTOR,

YWIYTNESSES 5 BY v MEA -W ATTORNEY A. E. STEVENS.

AUTOPHONE SYSTEM.

APPLIO'ATION 11.21) NOW-6, 1 0a.

Patented May 17, 1910.

a sannws sanm s.

WIT ESSES; INVENTOR.

W fiawea, 3". {LwLMM ATTORNEY A. E. STEVENS.

AUTOPHONE SYSTEM.

APPLICATION FILED NOV. 6, 1908.

Patented May 17, 1910.

,6 SHEETS-SHEET 4.

GTQQWQV. m f. m 4 I 7 22min aflwhwau ATTORNEY A. .12. STEVENS. AUTOPHONESYSTEM,

APPLICATION FILED NOV. 6, 190B.

Patented May 17, 1910.

6 BEBETS-BHEET 5.

INVENTOR (gawk A -mi m in; ATTORNEY WITNESSES A. E. STEVENS.

AUTOPHONE SYSTEM.

APPLIOATION FILED NOV. 6, 190a.

Patented May 17, 1910.

6 SHEETS-SHEET 6.

I plicity as to I group. Fourth, means conversation in a UNIT D STATES PTEN OFFICE.

ALTON E. STEVEN or FALL RIVER,

To SAMUEL H. COUCH,

MASSACHUSETTS, ASSIGNOR on HREn-FIFTHS on WOLLASTON, MASSACHUSETTS.

AUTOPHONE SYSTEM.

Serial a... 461,304.

Specification of .Letters Patent. Patented May 1'7; 1910, Applicationfiled November 6 1908. i

To all whom it may concern: Be it known that I, ALTON E. STEVENS, acitizen of the United States, residing at Fall River,'in the county ofBristol and-State of Massachusetts, have inventeda certain new anduseful Autophone System, of which the following .is a specification,reference being had therein to the accompanying drawing.

My invention relates to that class of automatic telephone systemsdesigned for use in small centers of population, or for private Whereonly a limited number of connections or lines is required.

The system illustrated herein is of one hundred lines, capacity.

Among the objects of my invention are the following :.-To produce asystem which will meet the' requirements of different classes of servicewith practically uniform or standard apparatus, and is of such.simrequire a minimum amount of lnspection, and to eliminate, as far aspossibleg causes of faulty'operation. The principal features of myinvention reside in first, means whereby several stations may becomeelectrically united in a group,

for the purpose of intercommunication. Second, means whereb stations sounited in a group are inaccesslble to other stations, and the'pa'rtiesto the group may converse privately. 'Third,means whereby additionalparties or stations may be embraced in the group and eliminated at anytime at the op..-

tion of the original members thereof, and may yet be unable ofthemselves to join the whereby inde' end ent communication may beestablished s multaneously. between members of any number of pairs orgroup'sfof telephone stations. Fifth, means whereby common" transmitterbattery may be supplied to local lines, and local transmitter battery besupplied at stations on longer farmer's lines, and the twoclasses oflines united for purposes of common system. Sixth, means whereby astation ona multi-party line may signal line and obtainin the maximumefiiciency in signaling. Eig th, means whereby a line merly busy calledas employed in public cuits' of 'the' autophone system,

another station on the same line by operating the calling station .maybe normally open at the central station to permit of eflicient signalinand a called line may be supplied by a ca ling line with current tooperate. its selector to an off normal position, for the purpose ofsupplying common transmitter battery to the called line. Ninth, meanswhereby the busy tone is made operative only when a call is actuallymade to a busy line, or a line in use. Tenth, means whereby a partycalling a, busy line busy line ceases to to the calling party, and meanswherebysaid calling party can communicate with the for party withoutfurther; operation except to signal said called party.

may be at once aware of the fact when said [I be busy, and is accessibleEleventh, means whereby direct current, and

alternating current, signaling devices may, wlth faclllty,be'interchanged in private systems. i i

In the drawings illustrating the principles involved- 1n my invention,and the best mode now known to me of embodying those principles,- Figure1 represents diagrammatically the circuits of the autophone system,

or villa e systems.

F g. 2 represents diagrammatica ly-the cir- I as employed Fi s. 3 4, 5

n private telephone systems.

diagrammatically de 'ilso cirrepresent 'cuits' employed in theautophoiie system.

1g. Grepresents a plan of mechanical details of a selector, While Fig. 7represents a plan of electrical details of same;- and Fig. 8..represents a left side elevation of same. Figs. 9, 10 represent detailsof construction. Fig. 11' represents diagrammatically a detail ofcircuits. 5 Fig. 12 is a diagrammatic representation of an alternatingcurrent signaling circuit, and apparatus which may be substituted fordirect current signaling circuit and apparatus shown in Fig. 1.

Reference is now made to Figs. 1- and 2,

for thepurpose of a general description of the autophonesystem.Diagrammatically represented are the associated with two telephonelines, either ioo circuits and apparatus 1 of which may throughoperationshereinafter described, call, signal, andbecomeelectricallyassociated with the. other for the purpose of communication.

L1ne9, 14, station A,F1g. 1, and the central station equipmentassociated therewith,

contemplate a common transmitter battery system with one or morestations connected to the line, yet in this case, one station on thelinecannot signal another on the same Line 50, 51 and the central stationapparatus associated therewith contemplate a long, or farmers line withtwo or more stations B, C, connected thereto, the central stationselector being controlled bya selecting relay 57, and the transmittersfed by local batteries 72,. 118. In this case, one station can signalanother on the same line.

The station A on line 9, 14, embraces a make-and-break impulsetransmitter 17, receiver 1, hook 2, transmitter 13, ringer 124,condenser 123, ringing key 41, and induction coil 10, 75. The impulsetransmitter 17 may be any one of several, well known to the'art.

Associated with the line 9, 14, at the central 'station is a selectorcomprising the following elements :-Selecting magnet 6 around which is anon-inductive shunt 62, a

connecting magnet 15, constructed to present high impe ance tosound-produced currents, a lockout magnet 79, a ringing or signalinrelay 127; also two banks of terminals, a l ne bank 24, and a lookoutbank 23.

The terminals or contact points in the banks are arranged radiallyaround a common center, all of theterminals of a particular class beingin the same plane. At the center of the are described by the terminalsis a shaft carrying two movable contact brushes,-a line brush 22, and alockout brush 21, insulated from each other and from the shaft, anddesigned, upon the rotation of the shaft, to contact successively theterminals in their respective planes. As the shaft -carrying the brushes21, 22, moves two steps'from normal position, the spring 25 is permittedto contact the point 26, thereby grounding said point and consequentlythe lockoutbank wire 38 of calling line 9, 14; the spring 28 being permtted on the first step, to contact point 29 for purposes to behereinafter made plain.

A'source' of signaling current-48, an impedance coil 480, and apparatus84, 85, associated with busy signal, and a battery 5, are used in commonby all calling lines in the system. The .current of battery 5 issupplied to the system throu h two bllS'rbflIS 4, 16, the latter beingTgroun' ed at 86'.

'Additional stations on line .9, 14, may be readily arranged and.provided with means.

to signal between said stations by supplying,

. for example, an impedance coil as shown at 114 station .13, andarrangingthe circuits to conform with thoseshown inconnection withringing ke v A farmers arty 1i;; 5.o,. 51, employing localbattery-jtransm i' 'on,. is i1lustrated, with I two station'sB,C,,p,onn,ected thereto.

' The sub-station equipment comprises the usual receiver 54, transmitter71, switch hook 55, ringer 52, condenser 122, impulse transcameos mitter87 ringing key 64, and in addition, an impedance c011 114, a localbattery 72, and an induction coil, having three windings," a primary 73,an intermediate 68, and a secondary winding 74, the action of which willbe hereinafter explained.

The central station equipment for line 50, 51, is identical with thatdescribed in connection with line 9, 14, with the following exceptions:In the place of the selecting magnet 6 is a selecting relay 57operating through its contact springs the selecting magnet 93 which isincluded in a local circuit. As the selecting magnet 93 remainsenergized during a conversation and is in a local circuit and ofcomparatively low resistance, it would ordinarily become overheated;therefore, for the purpose of preventing this, and of economizingcurrent, a suitable resistance 97 is included in series with the saidselecting magnet 93 upon the attraction of its armature 94 which movesthe spring 95 out of contact with point 96, thereby including theresistance 97 in the local circuit.

To. obtain the maximum efficiency upon a long line as 50, 51, ,themagnets 57, 58, have necessarily many more turns of wire than magnets 6,15, through which common battery is supplied to the transmitters and areof much higher resistance.

Reference is now made to Fig. 2. It illustrates dia rammaticallythe'circuits and apparatus o the autophone system in a form which isbest adapted to private telephone systems, and which is a modificationand simplification of that shown in F igl 1.' A common wire 286, asshown, or two wires as 9, 14, and ground 86, 20, Fig. 1, may be used,but the former common wire-is preferable. Springs 228, 260, move out ofcontact with points 229, 261, and into contact with points 236, 243respectively, when their respective selectors move from normal position.

The preferred form of each selector at the central station, for eithersystem shown in Fig. lor Fig. 2, embraces the following three elements:-selecting magnet 206, connecting magnet 215, and lockout magnet 380theline relay 57 and ringing relay- 44, Fig. 1, used only in the villagesystem, being preferably mounted separately and not mechanically'combined with the selectortherefore the foregoing description of thesaid three ma nets of each selector shown in Fig. 1, will su ce forhhedescription of each selector shown in Fig. 2.

The method of using direct current signaIingKdeVices is illustrated inFig. 2 where,

stance ersed,.by the sound-produced currents, is in- J dicate'd by heavylines,both' in Fig- 1 and i which I will now "describe;

I the called line,

; and

i v, Common battery 5, see also "Fig. 3, is supplied to the transmitter13 through bus bars 4, 16, resistances6', 15," and primary '10. v Thebrush 22 connects the calling with the circuit, when connection iscomplete, being from wire 14, Fig. 1, through springq8 points 81,31,,spring 30, brush; 22,- bank point and wire140,.contacts 42, 59, 60,61 to wire 50. In other words,

the brush 22 bridges the impedance coils 15,

ances 62, 63, to permit sound-p'roducedcurcalled line, and ings 68,119,of

V windings,

58; otherwise the ductive,and so constructed as to present highimpedance {to sound-produced currents,

would preventtransmi'ssion between the two.

lines, even though same busfbar'16.

The inductive resistances 6, 57' are bridged by non-inductive resist:rents to pass ,aroundthe' said inductive resistances. Condensert may ofcourse be used in place of the said non-inductive re-v s'istances.Battery current also flows from 5 through bus-bars 4, 16, see Fig."3,,tothe the receivers at both stations are removed from their hooks. IY i "A comparatively small amountof current however flows through'thesaid intermediate thexcomparativelyon account of high resistance of therelay magnet 5.7, and of the impedance coil .58; ing through these coilshowever being suiticient for the proper control of the central Sound,'or articulate speech will cause through thelinediuin of the transmitter13, variations of the resistance" of the circuit to the calling stationA, which will cause in turn corresponding fluctuations of currentflowing to the called line and through the intermediate windings 68,119. To describe the 028111131011 more particu larly, a sound protransmitter 13, will cause agreater or 'less amount of current tofi'owthrough the'calling station circuit, If-theresistance is lowcred,the diflere'nce called line' will. receizvelless current; if'however"the resistance or; the cal-ling circuit is inc eased the potentialof thebattery his inbattery stations associated therewith,

the operation of battery 72 is permitted-to flow Tl tral battery 5resistance 15, which is in they be connected to the through intermediatewind stations A; and B, providing.

the .current-flow- 68 from battery in winding 68 opposes the directionof the fit of the combined currents. I current in intermediate winding68 coincides uced adjacent to the the flow of of potential of the bat-'tery will be lowered at the point where the two connected lines meet,therefore the creased at the point where the two lines meet, resultingin the called line receiving an increased amount ofcurrent. Thesefluctuations of current in the called line afiect through the medium ofintermediate windings 68, 119, the secondary windings 74, 120, thereceivers 54, 115, which are thereby in a well-known mannencausedtoreproduce the sounds transmitted from station A. If

however, a sound is produced adjacent to the transmitter 71, theresistance of its local circuit through primary 73 is thereby varied anda greateror lessamount of current/from through said by induction, 7winding 68. 1e amount of current flowing from thecenthrough theintermediate winding 68 varies as the direction of the sound producedcurrents in the said intermediate winding coincides with, or opposes theflow of current from said battery 5. The

primary 73 thereby producing currents in the intermediate consequentvariation of'current flowing to the called line variesOOIIGSPOIlCllIlglYlZhB amount of current fiowingvtovthe calling line,in'a manner already made plain, and through the inductive relations ofprimary 10 and secondary 75,- the receiver 1 is caused-to reproduce the.sounds transmitted by transmitter 71., i

The receiver at station 0 is affected by variations in thelocal circuitat station B or vice versa, in the following manner :--A normal amountof current flows to the line from batter 5, part of which flows througheach of the intermediate vwindings 68, 119. In the intermediate winding68 there may be produced through the medium of the transmitter 71,battery 72, and inductive relation of the primary windings 73 to saidintermediate winding, a series of currents of varying intensity, andalternating in character. These currents oppose or reinforce to agreater or less degreethe current flowing through said intermediatewinding 5.. If the induced current current from battery 5 through saidwinding, it coincides winding 119 receives momentarily the bene- If theinduced with the direction of flow of current from battery 5 throughsaid winding 68, it opposes current of said battery 5 throughintermediate winding 119, thereby reduc-z ing for the moment theamountof current I through, said winding 119 these fluctuations incurrent influencing by induction thesecondary winding 120 and hence thereceiver 115.

rent from battery 5,

but was open at each end with stations as B, t connected across with thedirection of how ot saidlbattery 5 'througlrthe intermediate "winding 119"of"station' C, therefore the f however the line received no curasshown, conversation could still take place between stations, as currentsinduced in the intermediate winding at one station would flow throughthe intermediate windings at other stations and consequently affect thesecondary windings and receivers at those stations. 1 v

Fig. 4 illustrates diagrammatically the circuits and apparatus of a busytone or signal, designed to notify a calling party if the called line isin use, or inaccessible to said party, and herein resides the ninth feature of my invention. What is illustrated is assumed to be part of thesystem shown in Figs. 1 or 2; and I will now describe its operation.

The lockout magnet 79, becomes energized when the brush 21 contacts abusy or grounded terminal in its bank 23, as will be hereinafter madeapparent, and attracts its armature, causing spring 80 to contact point82, thereby completing .a circuit from the busy wire 83 to the callingline. A busy tone or signal is produced in the wire 83 in the following,manner:'Upon the lockout magnet 79 becoming energized the spring 111 iscaused to contact point 112 thereby completing a circuit through primarywind ing 403 of an induction coil ortransformer, battery 404, busymagnet 405, armature 406, point 407; the above circuit producing inawell-known manner a vibration of the armature 406, the resulting seriesof electric impulses in the circuit causing currents to be lnduced inthe secondary windm 84 -which, while lockout magnet 7 9 is energized,

is included in the circuit to the calling station. Wires leading to,contacts 111, 112, are multiplied in to all of the selectors in commonas at 401, 402, so that the busy signal apparatus may be operated by anyselector.

Any one of several forms of busy tone apparatus well known to thoseconversant with the art, may be substituted for the one shown.

Fig. 5 illustrates diagrammatically the method of connecting the bankwires to the terminals of the lookout bank to permit a station on aparty line to cause his central station selector to connect to that linefor the purpose of signaling another station on the same line. Thismethod consists in disconnectingin each selector its own individuallockout terminal from its lockout bank wire. As an illustration, sixbanks of lockout terminals'are' shown, numbered 1, 2, 3, 4, 5, 6,respectively, their grounding, or olf normal springs as 78, and theirindividual bank wires being designated by like characters. If No. 1desires to signal another station on his own line, he calls in the usualmanner. The selector moving from normal position causes bank wire 1 tobecome busy or grounded through spring 78 and point 77 thereby groundingor making busy the terminal 1 in all of the selectors in the group withthe exception of his own selector in which bank wire 1 is disconnected,therefore his own selector can connect to his own line while otherselectors will be locked out. Likewise N0. 2 calling 'would ground andmake busy the terminal 2 in all of the selectors except his own; and soon. I

Having'completed a general description of the construction and operationof what is disclosed in Figs. 1, 2, 3, 4, 5, I will now consider acentral station selector which is of standard construction and isdiagrammatically shown in Figs. 1 and 2.

Figs. 6, 7, 8, 9 represent details of a central station selector. A bedplate 601, Fig. 8, forms a base on which the several elements aremounted. A cup 660 is forced up from the base to provide a suitableplace for the motor spring 665 whichholds the shaft 630 in, or returnsit to, normal position. The inner end of the spring 665 is fast to theshaft 630, while the outer end is looped over one of pins 641 of anadjusting disk 640, and spread by the other pin. 'The disk 640 is heldin a circular groove under cup 660, in the lower side of plate 601 byscrews 649 which may be loosened, and the disk turned to adjust thetension of the motor spring 665. A frame 617 is secured to the plate60l-at each end, as shown, and serves as the upper bearing for shaft630, the lower bearing being in t e center of the cupped part 660 of theplate 601. The shaft 630 carries at one end a ratchet wheel629, and atthe other end two contact brushes 221, 222, Figs. 7, 9, also a pin 650,Fi 7, which operates the springs 225', 228. selecting magnet 206 issecured toa yoke 602 which forms part of its magnetic circuit and whichis in turn secured to plate 601. An armature 603 is pivoted at 604 tothe yoke 602, and is designed to be attracted by the mag!- net 206, uponthe latter becoming energize A spring 607, adjusted by a stop 608,returns the said armature 603 to normal position. An extension 605 ofthe armature 603 carries a pawl 606 which upon attraction of armature603 by selecting magnet 206 engages the ratchet wheel. 629 and steps thelatter around, one tooth for each attraction of the said armature 603.Two pieces are punched up out of the frame 617; 609, Fig. 6, which actsas a stop for the pawl at the limit ofits forward movement, and 610which lifts the )awl from engagement with the ratchet whee 629 at thelimit of its backward movement; the selector being shown in an active orconnected position. A lock 618 is pivoted to the frame 617 by a screw,its

free end being engaged and moved by the a pawl 606 when the latter acts;the lock bemg of such shape as to prevent the inertia of the movingratchet wheel from throwing a eeaeoe out said pawl 606 when the latterreaches the'li nit of its forward movement. Secured to the lock 618 is aflat spring, the-.free end of which is formed into two projecting parts;one619 extends through a Suitable aperture in the said lock,- the other620 is bent backward, both for purposes to be hereinafter explained. 1 aA dog 616 is secured to a shaft 615" which has an upper bearing in thefra1ne617' and a lower bearing in plate 601. One en'd'of said dog 616 isdesigned to engage the ratchet wheel 629 and hold the vlatter"in eachsuccessive position where it may "he stepped by the operation of theselecting magnet 206. The other end is cut down around the lock 618forming a slot inwhich the said lock may work and permit the two parts619, 620 of its spring to engage alternately the twosides of the slot,forming an v escape movement between the dog 616, and at n rm l n mi g psi i ns; H lock 618 which is-operated by the pawl 606. rangementcontemplating the use of the A spring 621 tends to hold both thelock t'hlrd, fourth and fifth te m als for trunk 618 and do}; 616 'in'theirnormal positions. l nes, one hundred erminal o gular An extension 614:of dog 616 is designed to 111168- I, g i

be engaged by piece 613 on shaft" 612'for Fig. .10 represents amechanical means, purposes to be'hereinafter made plain. and 1g. 11 anelectrical neans,.for accom- A connecting magnet 215 is secured topl'ishlng a certa n object in connection with the plate 601 by twononana'gnfie supports a party on a party line calling another party 631.The said magnet 215' constructed O11 thesame line- I prefer, however, toem- 95 to present a high impedance to sound-proploy the latter means,which will. now deduced currents. It is also designed to atscribe. ,jtract an armature 611 which is secured to In ringing out on a calledline, it isnecesthe shaft 612; this attraction causes the saly tohavethe called line open at the cenpiece 613 to engage and move theextension tral ,statioinseeFig. 1, or, if closed, it must 100 GM of dog616 thereby moving the latter out be through high impedanceas 180,otherwise of engagement with ratchet wheel v629. there would be atendency to short circuit Through the shaft 612 is a pin 622, which theringing circuit and prevent'the proper normally operates the. springs631, 632, 633, amountfrom reaching the substations.

40 but this operation, of the pin may be pre- When the ringing relay 4Ais energized from 105 vented by an extension 627 of armature 625' acalling station, as A, contact is broken beof lockout magnet 380 forpurposes to be tween spring 46 and point .49, and springs hereinafterexplained. a 4.5, 416 are caused to contact points 47 which At the lowerend of the shaft 612, Fig. 7, are connected to a suitable source ofsigis a pin carrying an insulation 646, and at naling current 48; thesaid current is thus the-lower end of the shaft 615- is a pin supplieddirect to the-called line, an d no carrying an insulation 647, both tooperate clifiiculty is presented when "one line calls the contactsprings 330, 332, 331,235,187, another. When,- however, one stationdefor purposes that will appear later; sires to signalanotherstation onthe same 50 The bank Fig. 7, is secured to the line, arcertaindiflicultyarises. The select- 115 plate601 on the side opposite the apparaingrelay 57 .of a calling'line must remain tus shown in Fig. 6; the viewhowever is energized to hold the selector upon the conseen from the samedirection as Fig. 6; the nection to the called line, as when theconplate 601 and apparatus shown in Fig. 6 benec'tion is completed, allother means for ing removed. holdingsaid connection have been removed.

The lockout magnet 380, Fig. F 6, is se- It will be evident that ifaparty at station cured. to a yoke 628 which isin turn secured B wishesto signal station CV, he must to plate 601. its arn1ature625 is pivotedat while operating his own ringing relay 44, 626 to the yoke 628; andthe extension 627 maintain aflow of current through the 'se 60 of thearmature 625 is designed to operate lecting relay 57 to prevent thelatter from 125 contact springs .111, 112, 280, 281, 282. causing arelease of the selector, for con.-

Referring particularly to Figs. 7, 8, 9, the n'eoting the selector tohis own line is the bank terminals as 651, also at 223, 2241, are onlyway for supplying ringing currentto secured in insulating material and.clamped the line. lhis 1s perferably accomplished,

together y the-two metal rings 661. Part see Fig. 11, by supplying therelay 57 with 130 of the upper ring is cut away in Fig. 7 to show thespacing of the terminals. The brushes 221,222, are secured to the-shaft630, and when said shaft rotates the said brushes, contactin successionthe terminals 7 as '1in their particularplanes of movements. An electriccircuit-is maintained to said brushes 2'21, 222 during their entireoperation, through the medium of the 'feeder brushes 64:8, 670,

The supports642, 6 13, Fig. 7, secure their a particular groups ofcontact springs to the lower side of plate 601. Spacings as 644, Fig. 8,mainta n the proper relative positions between thepla-te 601" andbank.223. so The bank terminals in Fig. 7 are spaced [one hundred andeight-to the circle; three being left] out to make room for the feeder'bru'sh 648; the two; terminals 652 being left dle as restingtermlnalsifor the. brushes 221 4 an additional spring 691 and contact692, andthe ringing relay 44 with an additional spring 690, the latterspring being so arranged as to contact the point 49 before the spring 46breaks contact with said point 49.

Now if .the selecting relay 57 is energized as on a calling line, andthe said calling line energizes ringing relay 44 to signal on said line,the spring'690 contacts the point 49 thereby maintaining an activecircuit through the relay 57 from bus-bar 4, through said relay andpoint 49, springs 690,

691, point 692 to opposite side 16 of battery plished mechanically asshown in Fig. 10, by

placing the ringing relay in'such mechanical 1 relation to the selectingmagnet as 206 Figs.

6, 10, that they may operate as illustrated. The armature 603 issupplied with an extension 686 designed to be engaged by a 7 spring 681secured to armature 680 of ringed, the spring 681 engages the extension686 ing relay 44. If the latter relay is energized duringthe timethe'armature 603 is attractthereby holding and preventing the pawl 606from disengaging the ratchet 629 even though ,the selecting magnet 206is de'nergized through the breaking of the -connec.

tion between contacts 46, 49. If the selecting magnet 206 is deenergizedwhen the ringing relay. 44 is energized, this being the case when oneline calls 'another,'the extension 686 is in the path of the spring 681,but there is enough flexibility to this spring tolpermit the armature680to operate proper y.

I will now explain the coiiperative action of several elements of theselector, and will first consider the lockout magnet 380, Figs, 2, 6,and its relation with the connecting magnet 215. When a call is completeto a desired line, both the selecting magnet 206 and the connectingmagnet 215 remain energized, whether the called line is busy or not.Also the lockout magnet 380 must remain energized while the selector isconnected to a busy line; therefore some means must be provided forpreventing the energized connecting magnet 215 from caus ing the spring232 to break from point 233 and thus to prevent the lockout magnet fromremaining energized when connected to a busy line. The means is shown inFig. 6. With the connecting magnet 215 denergized and armature611 innormal position, the spring 232 is forced by insulation 623 into contactwith spring 233, its normal position, although the tension onspring 232isin such direction as to cause it to tend to contact the spring 231,and is normally permitted to do so while the connecting magnet215 isenergized. If, however, the called line is busy, the lockout magnet 380is energized, in a manner to be hereinafter explained, and by reason ofthe consequent attraction of its armature 625, the extension 627prevents the spring 232 from breaking contact with spring 233.

Having described the construction and operation of the separate elementsof the selector, there remains to be explained their cycle ofoperations.

The selector shown in Figs. 6, 7, 8, 9, is in an energized or connectedposition. Now, if the receiver is replaced at the station controllingthe selector, the selecting magnet 206 and connecting magnet 215 wouldbe deenergized, resulting first in the withdrawal of the pawl 606 fromthe ratchet wheel 629 and the consequent return of that member, andhence of the contact brushes 221, 222, to normal position by reason ofthe motor spring 665. The lock 618 would follow the paw1606 to the limitof the slot in the extension of. the dog 616 in which it plays. Asarmature 611 of connecting magnet 215 returns to normal position, thepiece 613 disengages the extension 614 of dog 616, thereby permittingthe latter to move toward engagement with the ratchet wheel 629. It isprevented however from engaging the ratchet 629 by reason of the part620 of the spring secured to the lock 618 which engages the edge of theslot in which the lock plays. The selector is then in normal position.Should the party make a call, the selecting magnet 206 is energized bythe operation of the impulse transmitter at the calling station, anumber of times corresponding to the number of the desired line. Theratchet wheel 629 is thereby stepped around'a number of teethcorresponding to the called line, and hence through the medium of shaft630, the brushes 221, 222 are moved into connection with the bankterminals of the desired line. The first action of the said selectingmagnet 206 causes the pawl 606 to engage and move the lock 618 to theposition shown which causes the point. 620 to release the side of theslot in the extension of the dog 616 thereby permitting the said dog 616to engage and hold the ratchet wheel 206 in each successive position,into which it may be stepped by action of selecting magnet 206.

Before the interruption of the final impulse, a circuit is completedthrough the calling station which causes the selecting magnet 206 toremain energized and thereby hold the selector in its connectedposition, and the connecting magnet 215 to become energized and attractits armature 611 which causes the dog 616 to disengage the ratchet wheel629; the point 619 engaging the inner side stance of the slot in theextension of said dog 616, and locking the latter out of engagement withthe ratchet wheel 629. It-has been mentioned that the shafts 612, 615;extend down through the late-601, and carry insulations 646, 647,.w ichoperate certain contact springs. Referringto Figs. 2, 6, 7, 8, when thearmature 611' of the connecting magnet 215 is attracted, the two shafts612,

615, are caused to turn in opposite directions;-the shaft 612 causingthe springs 330,

pulse transmitter thereby completing interruption of the 235 tocontactlthe springs 331, 237,, respec* tively, and the shaft 615causing" the spring 332 to follow, but not to contact the spring 330.The spring 332 is now locked in this position by reason of theengagement of the point 619 with the dog 616, and must so remain whilethe selecting magnet 206 is energized. The connecting magnet 215 may nowbe deenergized in a manner to be later described, and. permit the spring330 to vdrop back into contact with spring 332 for the purpose ofsignaling the called station. This may be repeated by the calling partyuntil the called party replies.

At the first stepof the selector from nor desires to communicate withstation 13.. The

receiver 201 is removed from hook 202, and if station B is No. 2 theimpulse transmitter 217 is operated to cause the springs 218,219 tocontact each other twice, thereby completing twice the followingselecting circuit from battery 205 through lecting magnet 206, wire 209,point 203, hook 202, springs 218, 219, common wire 286, to bus-bar 216and opposite side of battery 205. The selecting vmagnet isthereby'energiz'ed twice resulting in the brushes 221, 222, beingstepped to the second terminals in their re spective banks. Beforethe'interruption of the final contact between springs 218, 219, thesprings 211, 212, have been caused, in a well known manner, by theaction of the im- 217,- to contact each other, battery circuit which ismalntained after the final selecting contact, and is as follows':--frombus bar 20 1 through selecting magnet 206, wire 209, point 203, hook202, transmitter 213, primary 210,

spring 211, 212, spring 228, which when the 221, 222, are now connectedto to line brush 222 is open at called lines are thus spring229spring236 for purbus-bar 204C, se-

point 220, key 241,

a common transmitter pleting the circuit to the other side of battery205, and causing the selecting magnet 206 to remain energized, and theconnecting magnet to become energized. The brushes their secondterminals inthesdirection indicated by the arrows, to which are alsoconnected the bank wires239, 240, of thecalled line.

It should be observed that normally wires as214, 250, are open at thecentral station end, and have a normal connection to their line bankwires. that during the time of selection, the circuit spring 330. Forconvenience we Wlll hereinafter call bus-bar 20 1 positive battery, andbusbar 216, negative battery. As thecalling se-' 'lector moved fromnormal position, spring 225 was permitted tocontact the point "226thereby connecting negative battery 216 to bank wire 2380f the callingline, and upon the connecting magnet 215 becoming energized afterselection and causing spring 232 It should also be observed to contactpoint 231, negative battery 216 is therebyconnected to the brush 221,and to the lockout terminal, and hence the lockout wire 239 of thecalled line; both calling and rendered busy or inaccessible to othercalling lines, in a manner to be hereinafterdescribed. The connectingmagnet 215has, upon becoming active, also caused springs 330, 235, tocontact the points 331, 237, respectively, and caused the spring 332 tomove and become locked ad jacent to, but not in contact with, spring330.

Station A is now in a position to signal stationB, which is accomplishedby pressing the key 241 into connection with the point 220, therebyshort-circuiting and deenergizing the connecting magnet 215 in thefollowing manner :The said connect ng magnet 215 is' energized frompositive battery 204 through the resistances of selecting magnet 206,transmitter 213,"pr imary 210, and itsown resistance, to negatlvebattery 216. Whenkey 241 is operated the circuit is as follows :-frompositive battery 204 through selecting magnet 206 which remains.

energized, line 200, point 203, hook 202., to common wire 286. which isof practically no resistance, back to negative battery 216, therebyplacing the connecting magnet 215 with resistances 21.0,

213 in series, in multiple with the common wire. As the connectingmagnet is thus deenergized, the spring 330 is permitted to drop backinto contact with spring 332 there by completing contacts 332-330, and280-281, tobrush .222, bank wire 240, contacts 261-260, di-

rect current ringer 252, contacts 270-4269, to common wire 286; theringer 252 being caused, in a well known manner, to operate and. tosignal the called party, who there the following signaling cirsuite-frompositive battery 204, through signaling t The called line selector mustbe out of' normal position to permit the spring 260 to contact the point243 for the purpose of supplying common transmitter battery through theconnecting magnet 258 to the called line;

a result which is attained in the following manner, and which in volvesthe eighth feature of my invention :As the receiver 254 is removed fromhook 255, an energizing circuit is completed from positive battery 204through selecting magnet 257, wire 251, point 256, hook 255, transmitter27-1, primary 268, springs 267266, wire 250, contacts 260261, bank Wire240, brush 222, contacts 281 280, 330-331, 228-236, connecting magnet215 to negative battery 216. Selecting magnet 257 is thereby energizedand steps the called line selector out of normal position, and thecalled line now receives its supply of transmitter battery cur-- rentthrough its own connecting magnet 258. The spring 260 is caused to movefrom contact with point 261 and into contact with point 243 as thecalled selector steps from normal position, and the connecting magnet258 becomes energized and causes spring 242 to contact point 259,thereby maintaining a connection to the calling line, which had beenmomentarily interrupted by breaking of connection between contacts260--26l.

It should be noted that when the springs 228235 of the calling linecontact their points 236--237, and the springs 260-242 of the calledline contact their points 243259, the two connecting magnets 215, 258are in multiple, whiclr would prevent a called station from making asubsequent call until 'the calling station released his connection, asboth said magnets 215258 would remain energized through the completedcircuit to the calling station, were it not for the fact that when thecircuit is interrupted at the called station, and the selecting magnet25'? is thereby deenergizod, thus causing the selector to return tonormal position, the spring 260 is caused to break contact with point243; the connecting magnet 258bcing thereby removed from the circuit andbecoming deenergized permits contacts 242-259 to separate, and removesthe said connecting magnet 258 from further connection to the callingline, until the called. .selector has again moved out of nor1nalposition and a circuit completed through the called line, either throughmak-' ing a-connection to a third line, or through removing the receiveras in replying to the calling station. The calling line has'thereforetwo connections to the called line :-the first throu h point 261 for thepur ose of i8 called line, which is ot erwise open, the second throughspring 242, that connects the lines for purposes of conversation, andwhich second connection includes desired, al of which results in thereturn of station Bs selector to normal position by reason of theinterruption of its h cuit at springs 266-267 and in spring 260 breakingcontact with point 243; the connecting magnet 258 becoming therebydeenergized and causing spring 242 to break contact with point 259. Thespring 260 however immediately contacts again the point 243, as theselector moves out of normal position to connect to the desired line,thereby severing all connection between stations A and B until theselector of station B has completed the connection to the third line,and also completed its common battery circuit through the springs266267, whereby the connecting magnet 258 is again energized. Thebrushes 301-302 are now connected to the terminals of the third line inthe same manner that the brushes 221, 222 of station As selector wereconnected to the line of station B.

It now remains for station B to signal the line called which isaccomplished by pressing the key 264 into contact with point 265 whichwill cause the connecting magnet 258 to become deenergized in a manneralready ex lained in connection with station A, thereby causing spring305 to contact spring 307, and to complete a signaling circuit from)ositive battery 204 through said springs 30 -305, and 30830$) to brush302 and bank wire of the third line and thence through the ringer to thecommon wire and negative battery 216, as was the case in sig nalingstation B. It will be observed that as the connecting magnet 258 isdeenergized short-circuiting same by means of the com- .mon wire 286 forthe purpose of signaling,

the connecting magnet 215 which is in mu tiple, will also have atendency to ccomc deenergizcd, which does not take place however as thecontact between spring 242 and point 259 is immediately interrupted,thereby disconnecting station A from station B while the latter issignalin The third station, upon replying could now call a fourthstation, and the fourth a fifth, and so on; and thus several stationsmay be placed in communication.

olding cirtacts277-278 with bankwire I feature of my invention isinvolved in a private or lockout device. It has been made'obvious, how aselector-in calling, connects negative battery 216 to its lockout bankwire all of theselectors, and how a calling selector connects said ne-ative battery 216 to the lockout bank wire 0 the called line; there-The second fore, the lockout bank Wires of two or more.

out magnet 380 .to positive battery 204'; the

lookout magnet 380 becomingthereby energized and causing spring 280 tobreak from contact 281 and to contact point 282, thereby first severinall connection between thecalling line, and its line brush 222, whichrests .on the line terminal of the called line, and,

- through the and point 331, connecting tion ll remains out oftnormalposition.

upon the connecting magnet 215 becoming energized and causing contactbetween spring the calling line to the wire 282 in which is roducedmedium of the secondary 284 as has been explained in connection WithFig. 4, a busy tone, the circuit being as fol owsz-from line-209 throughshunt 262, bus-bar 204., condenser 285, secondary 284, wire 283,contacts 282, 280, 3307-331, to wire 214.

It should be borne in mind that the lockout magnet upon being energizedprevents spring from breaking contact with point 233 even when theconnectingmagnet 215 is energized.

It will be evident from the above that any number of stations connectedin pairs or groups, can converse privately and remain inaccessible toany calling stations, wherein the second and fourthfe'atures ofmyinvention are embraced.

The description of the tenth feature of my invention now consistentlvfollows, as we have station FA connecte to the busy line of station B.The busy tone Will be repeated to station A as long as the connection ismaintained, and the selector of stathe selector of line Bshould berestored calling line from the busy tone, and conwhich is multipliedinto If normal, position however, causingthe locknecting said callingline brush 222 which rests on the line terminal of Bs line. The

party' at station A knows immediately by the disappearance of the busytone that he now has access to the called line and that station E can besignaled in the usual manner with-- out repeating the. operation ofcalling.

The third feature of my invention z -Several parties at dillerentstations are con versing, when it is decided to refer certain; matter toa is not to be permitted to j o1n 1n the general] conversation;'the lastparty called may call this party, and any one or all of the members ofthe group may converse with him,

and after desired information has been'obtained, he may be eliminatedfrom the group simply by ing the connection.

It will be noted that the lookout magnet 380, is energized each time thebrush 221'- contacts a busy terminal while said brush is passing to adesired line. This however -1s in no wise detrimental to the properoperation of the system.

The eleventh feature of my invention will party out of the group, andwho the party who called him releasbe apparent from a study of Fig.2.The direct current signaling devices 324, 252,.may be replaced byalternating current signaling devices 3240, 2520, Fig. 12, and asuitablesource of alternating current, as. 3320, and 3070 bridged betweensprings 332-307, and the bus-bar 216; in which case the signalingcircuit would be as follows :-Suppose station A has called and becomeconnected to station B. The ringing button 241 at station A is operatedand causes the impedance coil relay 215-to release its'armature, therebycausing an alternating current signaling circn'it from source3320 to busbar 216, and to contacts 332, 330, 280, 281, brush 222, called terminaland bank wire 24-0,contacts 261, 260, signaling device 2520, contacts.270, 269,

of the apparatus pertaining to lockout de-' vices, lockout magnet 380andsprings 280,

to common wire 286 and back tobus bar 216; the alternating current 281,282, bank 223,'and wiring, brush 221, springs 225, 22,6, and 231, 232,233, and all apparatus pertaining to busy tone, could be eliminated, andthe system still possess all of. the features enumerated except that ofprivacy. i I

It has been herein mentioned that the contacts 225--226, becomeoperative upon the second step of the selector from normal 0.- sition.The reason ofthis is, should station A call and become connected tostation B,- the connecting ized during the time station A is signaling;t herefore the contacts 232-233 would close relay 215 would be denerthecircuit of the lookout magnet 380, to the lockout brush 221, and if,during this period, Bs selector should be stepped from normal positionby reason of the removal of the receiver at station B, contact between srings 277-278 would, in a manner alrea y described, operate the lookoutmagnet 380 of As line, provided said contacts 277-278 were madeoperative upon the first step of the called selector from normalposition.

I will now describe in detail the operation of so much of the completeautophone system as is illustrated diagrammatically in Fig. 1, andrelates to featuressix and seven of my invention; the mechanicaloperation of the system having already been made plain.

A ground return may be-usedas is illustrate or a common return wire asis shown in Fig. 2. lin the case of the complete system Fig. 1, however,in which lines may extend to a considerable distance, the ground returnis preferable.

Suppose a party at localbattery station B desires to communicate withstation A. The receiver 54 is removed from hook 55, and the impulsetransmitter 87 is operated in a proper manner to call station A whosecall in this case is one, whereby the following selecting circuit iscompleted: from ground 86 and battery 5, through bus-bar 4 selectingrelay 57 contacts 49-46, hook 55, contact 56 springh 88-89, to ground90. The selecting relay 57 becomes energized a number of timescorresponding to the number of the called station, thereby operatingthrough its contacts 91-92, the selecting magnet 93 as has already beenexplained, the said selecting magnet 93 causing the brushes 101, 102 tostep to the terminals of the desired line; the subsequent completedcircuit through station B rendering active the connecting magnet 58,thereby first making the called line busy by connecting ground 86,through contacts 100-98, and brush 101 to-the lockout wire '38 of thecalled line, and causing connection between contacts 105-106 therebyconnecting the calling line to its line brush 102 which-is now connectedto the line terminal and bank wire 113 of the called station A; thespring 107 having been also moved adjacent to the spring 105 for thelatter to contact for the purpose of signaling. To facilitate explanations I will hereinafter refer to bus-bar 4 as battery, and to bus-bar16 as.

ground To signal station A, the key 64 at station B is pressed'intocontact with grounded point 127, thereby shunting and deenergizing theconnecting magnet 58, in a manner already explained, and causing thespring.

105 to contact the s ring 107, thereby completing a ringing-re aycircuit from battegy 4, through springs 107-105,brush 102, be

- invention.

wire 113, contacts 35-36, ringing relay 127, to ground 16; the saidringing relay 127 becoming energized and causing spring 8 to break itscontact with point 7 thereby openin the called line and creating a mostfavorab e condition to receive signaling current; and now follows theseventh feature of my The springs 8-126 are now caused by action ofringing relay 127 to contact the points 125 which lead to a suitablesource 48 of signaling current, this current being supplied therethroughdirect to line 9-14, and causing theoperation of the ringer 124 throughthe condenser 123; the contact between 7 and having been first severedby the action of said ringing relay 127 It will be evident that on lineshaving only one station connected thereto, the condenser 123 may bedispensed with, and a means provided as, shown in contacts 207-208, Fig.2 for opening the ringer circuit when the receiver is removed from thehook. The station A now responds by removing the receiver 1 from hook 2,thereby causing the selecting magnet 6, and the connecting magnet 15 tobecome energized and to step the selector of station A out of normalposition; said station A obtaining its supply of common transmitterbattery through said magnets; the connecting magnet 15 causing spring 35to contact point 37 thereby completing the connection to station Athrough bank wire 113, contacts 35-37 and 29-28, to line 14.Conversation may now be carried on between stations A and B; theconditions having been already explained and shown in connection withFig. 3, with the exception'that the call isre-' versed. The calling andcalled lines have now been rendered inaccessible to. other lines,

and the called station can call, as has already been shown, a thirdstation.

Twill now explain the operation of the elements embraced by-the sixthfeature of my invention. a

It will be observed, in relation to the sixth feature of my-invention,that with the re-' ceiver 54 removed from the hook 55,. the normalbattery circuit. is from wire .50 through key 64, point 65, contacts66-67, intermediate winding 68, point 56, hook 55 to wire 51; thus thereis maintained aclosed circuit through the stat-ion, to hold the.

selectingrelay 57' and connecting magnet 58 energized after a call hasbeen made. Now, if key 64 is operated to signal a called station, thefirst object of the impedance coil 114 becomes apparent, for if thecircuit through the station is interrupted between key 64'and point 65,,the selecting relay 57 will become deenergized and cause the release ofthe connection. It is therefore necessary to maintain a closed circuitthrough-the station B while the latter. is signaling; and this closed-'circuit must are such that conversation may be carried on. It remainshowever for station E to signal station C. Station B calls the number ofhis owh line, the brushes 101-402 j being, thereby causedyto contact therepreture of the selectin his receiver 115 from ties at the two statons, on the same line may now converse,

sentati ve terminals of line 50-51, and the selecting relay 57 andconnecting magnet ecome and to remain energized. The signal at. stationG is, for instance, two rings; therefore the key 64 is operated, twice,causing the connecting magnet 58 to be twice dc energized (it beingenergized after each deenergization by current. supplied throughimpedance coil 480 to-line 51) and to complete each time the followingringing relay circuit; from battery 4,. brush 102, contacts 42, 43,ringing relay 44, to ground-16; the said ringing relay44 becomingthereby energized and causing spring 46 to open the circuit to the line51 at point 49, andj'causing springs 45-.46 to contact the points 47,source of signaling current 48 to--' become connected direct to'the line5051.resulting in the operation of all the signaling devices connectedthereto. ,ticular signal the party at stationC'rejmoves hook 116 and theparthe talking conditions being herein explained in relation to stationsB and C,.Fig. 3. I

It should be borne in mind that normally the severing of the connectionbetweenfcom' tacts' 49 and 46 would cause lay to become deenergizedconnection to be released the means i'llustratedin Fig. 11 for preventing same, or, the mechanical mean'sillustrated in Fig. 10 forpreventing. the arma- "magnet as 93 from the "selecting repermittingpawl 606 ing the ratchetwheel 629. i

' have now-described my invention in detail, and

fications which {may be suggested by experi-,. ment or experience,without material de arture from lnventlon.

the principles and/spirit of Desiring to protect my inyent'ion in thebroadest manner legally-possible, What I I claim is 1'. 'In an automatictelephonesystem, tele? phonelines; automatic I I H calling hne maybecome electrically assothrough contacts 107-405,.

communication; means calling and called lines .tricallyfassociated' witha third line for the I purpose of inter-communication, and meanswhereby. electrical current from a central .source may be supplied tothe transmitters at the connected stations; and means where-' therebycausing the In response-to his parother lines.

j phone lines;

and cause the were it not for:

(Fig. '6) from releashave illustrated and described thebestembodimentnowknown tonne of ciated with a to the structures ls-'- ,tricallyassociated tent to .IIorinal position.

means whereby a ated with a pa 11 ciated with 'a calledlinefor thepurpose or communication; means whereby the said calling line and calledline may become elec- ,trically associated with, a called third line forthe purpose of inter-communication and means whereby electricalcurrentvfrom a central source may be supplied to the transmitters 'inmultiple, tions. a a

- In an automatic telephone system, telephone lines; automatic meanswhereby a calling line may become electrically associated with a calledline for the purpose of communication;.means whereby the said callingand called lines may become electrically associated with a third ofinter-communication, and means whereby electrical current from a centralsource may besuppliedto the'transmitters at the con nected stations; andautomatic means for at, the. connected stag line for the purpose eachline to "restore itsoperstted apparatus.

to normal position.

3. In an automatictelephone system, telephone lines ;-autom at1c-meanswhereby a calling line may become electrically associated with acalled-line may become elecby said lines'may be made-inaccessible to 4.In an automatic telephone system, teleautomatic means whereby a callingline ma become electrically associated with a calledline for the purposeof communication trically associated with a third line for the purposeof inter-communication, and means whereby electrical. current from acentral source may bejsupplied to the transmitters at the connectedstations; automatic means for restoring the system to normal position;and means whereby's'aid lines are inaccessible to other lines.-

5. In an automatic telephone system, telephone lines; automatic'meanswhercby a calling line Ina become electrically assocalled'line forthe communication; means whereby, the said calling and called lines maybecome else-- with a thirdline for the P rp e f current maybe suppliedat theconnected stations; and automatic means .for restoring the sysforthe purpose of hereby the said means whereby the said calling and calledlines may become 'elecpurpose of I inter-communication; means wherebyelectrical tothe transmitters 6. In an automatic telephone system,tele-= phone line's; automatic means whereby a calling line mafiybecom'e ed line for the purposev of electrically associ communication;means whereby the said with a called line for the purpose ofcommnnication; means whereby the said calling and called lines maybecome electrically associated with a third line for the purpose ofinter-communication; means whereby electrical current may be supplied tothe transmitters at the connected. stations; automatic means forrestoring the system to normal position; and means whereby said linesare inaccessible to other lines.

8. In an automatic telephone system, tele- 'phone lines; automatic meanswhereby severalof said lines may become electrically united for thepurpose of inter-communication; means whereby one or: more of theremaining lines may be associated with said several lines, and automaticmeans whereby said one or more remaining lines may be disconnected fromsaid several lines.

' 9; In an automatic telephone system, telephone lines; automatic meanswhereby several of said lines may become electrically united for thepurpose of inter-communication; and means whereby one or more of theremaining lines may be associated with said several lines; automaticmeans whereby said one or more remaining lines may be. disconnected fromsaid several lines; and means whereby said several lines may berendered'in-- accessible to said one or more remaining lines. 10. In anautomatic telephone system,

telephone lines; automatic means whereby- 7 several of said lines maybecome electrically united for the purpose of inter-communication; andmeans whereby one or more of the remaining lines may be associated withsaid severallines; automatic means whereby said one or more remaininglines may be disconnected from said several lines; and automatic meanswhereby each' line may restore its part of the connection to normalposition.

11. In an automatic telephone system, telephone lines; a selectingmagnet and circuit associated with each line, whereby a line may becomeunited with another line;

a ratchet wheel cooperating with said selecting magnet, and-means toengage and hold said ratchet wheel; a-connecting magnet; apparatuswhereby said means may be caused by said, connecting magnet to disengagesaid ratchet Wheel when said line has become united with another line;and'means whereby the selecting magnet holds such union operative.

12. In an automatic telephone system, telephone lines; a selectingmagnet and circuit associated with each line whereby a line may becomeunited with another line; a ratchet wheel cooperating with saidselecting magnet, and means to engage and hold said ratchet wheel; aconnecting magnet; apparatus whereby said means may be caused by saidconnecting magnet to disengage said ratchet wheel when said line hasbecome united with another line; and means whereby the selecting magnetholds such union operative; and means whereby the selecting magnet uponbecoming deenergized, causes disconnection between the two lines.

13. In an automatic telephone system, telephone lines; a sub-stationassociated with each line, having a local transmitter circuit, closedwhen said sub-station is in use; for each line, a selecting magnet and aconnecting magnet; means whereby common transmitter battery is suppliedtherethrough to sub-stations in use; said magnets becoming therebyenergized; and means whereby said connecting magnet may be shunted, andthereby deenergized for the purpose of signaling a called sub-station.

14:. In an automatic telephone system, telephone lines; for each line, aselecting magnet; a ratchet wheel; a dog; said ratchet wheel beingoperated ste) by step by said selecting magnet, and sai dog holding saidratchet wheel at each step; a connecting magnet; and means whereby saidconnecting ma net upon becoming energized, causes sai dog to disengagesaid ratchetwhcel; and means whereby said dog may not again engage saidratchet wheel until said selecting magnet has'bcen deenergized and againenergized.

15. In an automatic telephone system, telephone lines; for each line, atelephone station, a selecting magnet, a non-inductive shunt for saidselecting magnet, an impedance coil, a central battery, and meanswhereby electrical current from said battery may be supplied to atelephone station through said selecting magnet and said impedance coil;a movable connecting terminal, whereby a path suitable for conveyingsound-produced currents, may be bridged across the impedance coils of acalling line and a called line, for the purpose of uniting said linesfor conversational purposes; an

- means operated by the impedance coil of a calling line, to signal acalled line.

16, In an automatic telephone system, telephone lines; for each line, atelephone station, a selecting magnet, a non-inductive shunt for saidselecting magnet, an impe dance coil relay; a central battery; and meanswhereby electrical current from said battery may be supplied to ateleplione'stationthrough the said selecting magnet to one limb of theline, and the impedance coil cameos.

relay, to theother limb of the line; a movable connecting terminalwhereby a path relay of'a calling line Lmay be operated to signal acalled line. i 17. In an automatic telephone system, telephone lines; animpedance coil relay for each line; a source of signaling current; a

movable terminal electrically connected to said source; a "connectingterminal which may be electrically associated with a called mit the saidline,

5& come operative and cause-said selectivaapline; means whereby theimpedance coil relay ,upon becoming. energized, causes the movab eterminal to move and to become locked'adjacent to the connectingterminal;

and means whereby the said impedance coil relay may, upon becomingde'nergized, perconnectin terminal to contact the said movable terminal,for the purpose of signaling a calledline.

- 18. In an automatictelephone'system,telephone lines onelimb of eachline-being associated with aselectingmagnet circuit, and the otherlimbbeing normally open at a central station; a'centralbattery; commonreturnvcircu'it connected to one pole of said battery; a signalingdeviceon each telephone to said common return open lines; and means .lmemay connect to the line, and connects circuit and to said wherebya'callin o en'line of a ca ed line the opposite pole 0 said battery, forthe purpose of operating the signaling device on said called line.

19. In an automatic telephone system, telephone lines; one limb of eachline being associated with a selecting magnet circuit, and the otherlimb being normally open ata central statkin; a central battery; acommon re. turn circuit connected to one pole of said battery; asignaling device oneach line and connected'to said'common return circuitand to said open limb; an impedance coil relay;

l and means whereby a calling line may, I through the agency of theimpedance coil relay, connect to the open limb of a called the purpose ofvice on said called line; y 20. In an automatictelephonesystem,'telephoneline's; one limb ofeach line being associated with aselecting ma the other limb being normal y on said line; and meanswhereby the re- .moval of the receiver from its hookicoma circuitbetween the selecting magnet letes limb, and the open limb; and meanswhere by a. calling line may-com lete a circuit to theopen limb of acalled 'ine whereby the selectingcircuit of the called line maybecalling telephone line;

the opposite pole ofsaid battery, for operating the". signalingdesociated with said line; sai 'et circuit, and open at a cen-' tralstation;a called line; selective apparatus associated therewith; atelephone station vparatus to move from normal position, to

supply common, transmitter battery to the called line through apparatusassociated with that line.

21. In an automatiqtelephone system, tele-= a signaling relay associatedwith each line; and means whereby a calling phone lines;

at will the saidsign'aling relay of a called line to signal a' stationon said called line; a

source. of signaling current; means whereby the signaling relay opensthe line to the called station, and connects to said openline i I saidsource of current, to operatea signaling device thereon. w

23. In an automatic telephone system, a a relay associated therewith; acalled line; a signaling rela'ly associated therewith; means whereby acal ing party may, upon completion of a'call,

through the agency of said relay, control at will the saidslgnalingrelay for the purpose of signaling a station on the calledline.

24; In an automatic tele hone' system, a.

telephone line; a calling statlon, and a called station thereon; aselector associated thereconnect to that'line; a selecting ma et'associated with said selector, and ho ding it in its connectedposition; a signaling relay with and operated by the calling station to:

associated with said line, said signallng rey i lay being controlled bythe calling station tion; means associated with said signaling relayvfor preventing the said selecting magnet from becoming deenergizedwhen'said relay for. the purpose of signaling the ca ed station] line isopened by said signalin' with and operated bythe calling station to 1connect to that line aselecting sociated' with the selector and magnet e5 oldin it 111,. itsconnected position; a si ahng re ay as for thepurpose of" signaling the called. stasignaling. relay' being controlledfrom the callingstatlon fon the purpose of signaling thecalled Jtation;

and means associated with the ,saidsignaling relay for preventing therestorationto ndlfmal of said selector, by. said sign'alin signaling thecal edstaticn thereon;

y 26. In an automatic ,.te1ephone'eyistem, f telephone lines; associfaI, tie a selector having a. bankoif lockout terminals tecl with each,

a movablelockout' tern] inal a lockout mag net and circuit, said cineuitbeing normally when said line is bpen'd .relayfont e purpose; of

closed to said movable lockout terminal, and

its multiple bank wire, a'lockout potential to its individual lockoutterminal in all of the other selectors in the system, for the purpose ofrendering a line in use-inaccessible to a calling line; eachmultiplebank wire be-j ing disconnected fromthe lockout terminal of itsindividual selector, for the purpose of rendering a line accessible toits own'selector.

2?. in an automatic-telephone system, a calling telephone line; atelephone station thereon;.a selector associated therewith, and

connected to'a called line; a local circuit in I said calling stationwhereby the said selector ma be held in connection with a calledlinewhile'the latter line is being. signaled; an

. impedance; the latter being included in the .local circuit of acalling station while said station is signaling, for the purpose ofpreventing the short-circuiting of the signaling current at a callingstation when the called station is on the same line.

28. In an automatic telephone system, telephone lines; associated witheach line, a se' lector having a bank of lockout terminals;

each selector having connection to a reprea sentative lockout 'terminalin the lockout bank of each of the other selectors; a busy relayelectrically associated with a movable terminal 'which may connect insuccession to thelockout terminals in its individual lockout bank; animpedance coil relay; the circuit of said busy relay being normallyclosed through contacts operated by said impedance coil relay, said busyrelay being thereby normally in a posit-ion to act when the movableterminal contacts an active lockout terminal; means whereby the saidimpedance coil relay of a calling line becomes energized upon thecompletion of a connection and thereby disconnects the said busy relayfrom its said movable terminal, and connects a lookout potentialthereto, for the pur ose of rendering the called line inaccessible toother lines.

, 29. In an automatic telephone system, telephone lines; associated witheach line, a selector' having a bank of lockout terminals; each selectorhaving connection to a representative lockout terminal in the lockoutbank of each of the other selectors; a busy relay electricallyassociated with a movable terminal which may connect in succession tothe lookout terminal in its individual bank,

the circuit of said busy relay being normally closed through contactsoperated by an mpedance .coil relay; said busy relay being therebynormally in a position to act when the movable terminal contacts anactive lockout terminal; and means whereby the said busy relay uponbecoming energized by reason of its movable terminal contacting alookout terminal upon which is a lookout potential, opens the circuitwhich would otherwise be established between a calling line and a calledline.

30. In an automatic telephone system, tele phone lines; associated witheach line, a selector having a bank of lockout terminals; each selectorhaving connection to a representative lockout terminal in the lookoutbank of each of the other selectors; a busy signal; a busy relayelectrically associated with a movable terminal which may connect insuccession to-the lockout terminal in its individual bank, the circuitof said busy relay being normally closed throu 11 contacts operated byan impedance coi relay; said busy relay being thereby normally in aposition to act when the movable terminal contacts an active lockoutterminal; and meanswhereby the said busy relay upon becoming energizedby reason of its movable terminal contactlng a lockout terminal uponwhich 1s a lookout potentlal, opens the cir-- cuit which would otherwisebe. established between a calling line, and a called line, and connectssaid busy signal to said calling line.

31. In an automatic telephone system, telephone lines; associated witheach line, a selector having a bank of lockout terminals; each selectorhaving connection to a representative lockout terminal in the lockoutbank of each of the other selectors; a busy signal; a busy relayelectrically associated with a movable terminal which may connect insuccession to the lockout terminals in its individual bank; and meanswhereby the said busy relay upon becoming energized by reason of itsmovable terminal contactin a lookout terminal upon which is a potentlal,opens the circuit which would otherwise be established between a callingand a called line, and connects the busy signal to said calling line; animpedance coil relay associated with said calling line which would no"-mally open the circuit of the busy relay upon the completion of aconnection, the circuit of said busy relay being normally closed throughcontacts operated by the said impedance coil relay; saidbusy relay beingthereby normally in a position to act when the movable terminal contactsan active lockout terminal; and means associated with the said busyrelay to maintain said circuit closed when a call ismade to a line inuse.

32. In an automatic telephone system, telephone lines; associated witheach line, a busy

